Dyed modified acrylonitrile and methacrylonitrile polymers



United States Patent Int. (:1. cosr 3/74 US. Cl. 26063 Claims This is a division of parent application, Ser. No. 129,- 556, filed Aug. 7, 1961, now US. Pat. 3,254,068.

This invention relates to a modified acrylonitrile polymer and to a modified methacrylonitrile polymer, said polymers having a greatly increased dye receptivity. In one of its aspects, the invention relates to a method for the production of a dyed modified acrylonitrile polymer and/ or a dyed modified methacrylonitrile polymer which comprises contacting said nitrile with a labile hydrogencontaining compound in the presence of a free-radical agent, or in presence of free radicals produced in situ by activating rays such as alpha rays, beta rays, gamma rays, X-rays and ultraviolet rays. In a further aspect of the invention, it relates to a product which can be obtained by contacting the modified polymer of the invention with an aqueous acid or base, as further described herein. In a still further aspect, the invention relates to the production of a dyed polymer.

In the field of polymers, considerable work has been carried out on the polymerization and copolymerization of acrylonitrile. Resinous polymers of acrylonitrile have been prepared, and acrylonitrile has long been used as a comonomer with conjugated dienes in the preparation of special types of synthetic rubber.

In the methods of the prior art, acrylonitrile is polymerized in the presence of free radical generating substances or catalysts. While acrylonitrile has been copolymerized with various polymerizable materials, a satisfactory modified polymer of acrylonitrile has not been obtained especially as this is related to dye receptivity. Acrylonitrile polymers, modified so as to obtain other reactive groups along the polymer chain, would be very beneficial. These reactive groups could be utilized to improve the dyeability and/or other characteristics of the polymer.

It has nOW been discovered that novel dyed modified polymers of at least one of acrylonitrile and methacrylonitrile can be prepared by contacting the unsaturated nitrile with a labile hydrogen-containing compound in the presence of a free radical agent or generator and then dyeing the polymers obtained. Modified polymers have been produced employing chemical sources of free radical agents and free radicals generated by activating rays. Of the activating rays, gamma radiation appears to yield modified polymers having a superior dye receptivity.

Accordingly, it is an object of the present invention to provide a method for the production of a modified polymer of at least one of acrylonitrile and methacrylonitrile. Accordingly, it is another object of the present invention to provide a method for the production of a modified polymer of at least one of acrylonitrile and methacrylonitrile having a greatly increased dye receptivity.

Other aspects, objects and the several advantages of this invention are apparent from a study of this disclosure and the appended claims.

According to the present invention, novel dyed modified polymers of at least one of acrylonitrile and methacrylonitrile can be prepared by a method which comprises contacting the unsaturated compound with a labile hydrogen-containing compound in the presence of a free radical generating agent and then dyeing the modified "ice polymer thus obtained. Also, according to the present invention, modified polymers of acrylonitrile and of methacrylonitrile of improved dye receptivity are obtained employing activating rays to generate the free radicals in situ, especially superior modified polymers being obtained by contacting the unsaturated compound with the labile hydrogen-containing compound under influence of ionizing radiation, e.g., gamma radiation.

More specifically, according to the present invention, there is produced a modified polymer of substantially increased dye receptivity by a method which comprises subjecting at least one of acrylonitrile and methacrylonitrile to contact with a labile hydrogen-containing compound in the presence of ionizing radiation, said labile hydrogen-containing compound being selected from the group consisting of and --OR, wherein R and n are as previously defined.

The modified polymers of acrylonitrile and of methacrylonitrile have the following structural characteristics:

wherein R is a 1 to 10 carbon alkylene radical, n is a whole integer of from 0 to 2, R is selected from the group consisting of primary and secondary alkyl radicals containings from 1 to 10 carbon atoms, R' is selected from the group consisting of -R,

and OR and x/ y is approximately 1-20 and wherein R"" is selected from the group consisting of hydrogen and methyl.

In the preferred form of the invention, R is methyl.

As stated, according to the invention, there is provided a method of producing a dyed modified polymer by steps comprising reacting at least one of acryonitrile and methacrylonitrile with a labile hydrogen-containing compound in the presence of a free radical agent, recovering polymer thus produced, and then dyeing the polymer. Dyeing of the modified polymers can be elfected by contacting the polymers with a dye solution, preferably aqueous. While acid, basic or neutral dyes can be used, the acid or basic dyes are preferred. The contacting of the polymer with the aqueous dye solution can be carried out at temperatures generally ranging from ambient temperatures up to the softening point of the particular polymer, and usually ranging from 25 C. to 75 C.

Some examples of labile hydrogen-containing com- )ounds which can be employed in the process of this inrention are nitromethane, nitroethane, nitrohexane, aceone, methyl ethyl ketone, methyl acetate, ethyl propion ite, methyl butyrate, n-hexyl acetate, hexyl caproate, 2,3- mtanedione, 7,8-tetradecanedione, 2,4-pentanedione, 2,4- iexanedione, 7,9-pentadecanedione, 2,5-hexanedione, 2,5- )ctanedione, 7,10-hexadecanedione, methyl Z-oxopropionate, ethyl Z-oxobutyrate, hexyl 2-oxooctanoate, methyl 3- xopropionate, propyl 2-oxobutyrate, hexyl 3-oxopropionrte, hexyl 3-oxononanoate, methyl 4-oxopentanoate, hexyl t-oxodecanoate, dirnethyl oxalate, dihexyl oxalate, dirnethyl malonate, di-n-butyl malonate, di-n-hexyl succiiate, acetic anhydride, caproic anhydride, nitrodecane, li-n-decyl ketone, decyl methyl ketone, octyl-n-heptyl ke-'- :one, 11,12-docosanedione, decyl-S-oxodocosionate, decyl icetate, methanol, ethanol, isopropanol, sec-octanol, nlecanol, acetonitrile, propionitrile, capronitrile.

The polymers prepared by the process of this invention are actually modified polymers of acrylonitrile and methtcrylonitrile in which the modification occurs during potymerization. The labile hydrogen-containing compound reacts with the nitrile groups attached to carbon atoms of the polymer chain. For example, when a mixture of acetone and acrylonitrile is contacted with ionizing radiation according to the process of this invention, the polymer has the following configuration, wherein the ratio x/y lies within the range of from 1 to nitromethane, methyl acetate, dirnethyl oxalate, acetic an 5 hydride, methanol, acetonitrile, the reaction occurs in an analogous manner as indicated in the following formulas. The compounds obtained are:

Mixture of nitromethane and acrylonitrile Mixture oi methyl acetate and acrylonitrile Mixture of dimethyl oxalate and methacrylonitrile Mixture of acetic anhydride and acrylonitrile Mixture of isopropanol and acrylonitrile H H /CH2C\ /CH2C\ The process of the present invention is carried out by subjecting a mixture of the above-described reactants to the action of a free radical generating agent, or ultraviolet light or ionizing radiation at temperatures usually within the range between 25 C. and C. The mol ratio of unsaturated nitrile to labile hydrogen-containing compound usually will be within the range between 1 and l/200. The pressure in the reaction zone is not critical, and will generally be within the range between atmospheric and the autogeneous pressure developed under closed conditions at the temperature chosen for the reaction. This pressure will generally not exceed 100 psi. It is preferred to agitate the reaction mixture during radiation.

Chemical sources of free radicals are peroxides, hydroperoxides, azo compounds and redox systems. Free radicals can be generated in situ by means of actinic radiation. Actinic radiation useful in the practice of this invention includes activating rays such as ultra violet rays having a wave length in the range of 100 to 3800 angstroms, and ionizing rays such as alpha rays, beta rays, gamma rays, X-rays, deutrons, protons, and neutrons. The ultraviolet rays can be supplied from mercury lamps or other equivalent sources. The ionizing radiation can be supplied from such sources as cathode tubes, accelerators, such a cyclotrons, synchrotrons, betatrons, natural and artificial radioactive elements, spent nuclear fuel elements and the like.

Representative chemical sources of free radicals which can be used include ditertiary alkyl peroxides such as di-tert-butyl peroxide and other peroxides and hydroperoxides such as alkyl hydroperoxides, alkyl peroxy esters, diacyl peroxides and the like. Azo compounds which can be used include those having an acyclic azo group, -N=N-, bonded to different non-aromatic carbons, i.e., aliphatic or cycloaliphatic carbons at least one of which is tertiary e.g., a,a-azodiisobutyronitrile, oz,ot'- azobis(a, -dirnethylvaleronitrile), and the like, such as those disclosed in US. 2,471,959 and 2,503,252. RedoX systems are normally employed as aqueous systems, using such materials as ferrous sulfate in conjunction with such reagents as pyrophosphates.

The amount of a chemical source of free radicals which can be used will vary widely, but will generally A 0.2 gram sample of this polymer was placed in 15 cc. of concentrated hydrochloric acid (36 weight percent HCl) and heated to reflux. After maintaining the mixture at this temperature for 6 hours, the acid was evaporated off. The remainign residue was placed range from 0.1 to 10 percent by weight of the nitrile in a Soxhlet extractor and extracted with anhydrous monomer, preferably from 0.5 to 5 percent on the same acetone to dissolve the polymer and leave NH CI bebasls. hind. The acetone solution was then evaporated to dry- The actinlc radiation WhlCh can be used to generate ness and the residue was analyzed by infrared. free radicals in situ in the method of this invention The infrared spectrum was consistent with hydrolysis Wlll generally have an energy level in the range of 3.l of the nitrile groups of the above polymer to yield carto 1 10 electron volts. The radiation dose rate will boxyl groups, thus the structure is indicated to be as generally be from 10 to 10 Roentgens per hour, and follows, wherein x/y is approximately 1.0. the total dosage is usually in the range from 10 to 10 Roentgens. A preferred total dosage is within the range 15 H f H\ of 10 to 10 Roentgens. A Roentgen is equal to CHzO iCH C/ 5.80 10 electron volts. (500E), I y

The mixture of unsaturated nitrile and the labile hy- 0:0 0 drogen-containing compound are contacted as herein ll exemplified and, at the end of the reaction time, the fi eiiii iw iofilfiiill$211131? ?lix lillfi tfiilll each of runs gram Sample of the n o P unhydrolyzed polymer was dissolved in warm 95 perreacted materials can be removed under reduced prescent ethanol, and the solution was added to approxisure. The products which are recovered are modified 1 matey 10 ml. of a 2,4-d1nitrophenylhydrazine-EtOH- polymers of acrylonitrlle and methacrylonltrlle. The

resence of the modif in mu 5 im roves the d H S0 -H O solution. An orange precepltate appeared. gbirt of th 01 mars y g g p p y Two drops of water were then added to aid precipitation. y e P Y The precipitates from the two runs were combined EXAMPLE I and dried, and the precipitate was then examined by infrared analysis. A run was carried out in which a mixture of acrylo- 0 nitrile and acetone was subjected to the beam from an th The i f i bands mdlcate that the Strumure of electron accelerator. e Preclpl a e was In this run, a solution of 5.3 grams (0.1 mol) of H f H\ acrylonitrile in 232 grams (4 mol) of acetone was OH2O CH2CT charged to a glass flask and irradiated with the beam from E Y an electron accelerator. The total dosage was approxi- :NH mately 5 10 Roentgens. The flask contents were then E placed under reduced pressure (10-20 mm. Hg absolute), H and the unreacted materials present were evaporated oil. The remaining material was a solid polymer, amount- N--H ing to 2.4 grams. The estimated molecular Weight of this polymer was 5001000. N02

Infrared analysis of this polymer showed the presence I of methyl groups, carbonyl groups, imino groups and -CEN groups, and the relative band strengths in the I infrared spectra established the presence of one CEN N02 group per 9 carbons, and one carbonyl and one imino group per 9 carbons. EXAMPLE 11 These conditions are consistent with the following A f d h structure, wherein approximately percent of the nitrile 50 f l 1 r nsd Was carrule bputhuzi w 10 l'IllXjEllI'GS groups have reacted with the ketone, i.e. werein x/y 0 acry omtne an ,Vanous a 16 y rogencontammg compounds were sub ected to the beam from an electron is approximately 1.0.

H accelerator. i L L These runs were carried out by the procedure of l I/y Example I, and in each run, the mixture was irradiated C-NH to a total dose of 10 Roentgens. The irradiations were carried out in glassware at atmospheric pressure and room 1 3 temperature. The results of these runs are expressed below in Table I.

TABLEI Charge Product Mols Grams Mols Labile H Labile H Wt. acrylonitrile acrylonitrile compound compound grams Appearance 5.3 0.1 Acetone 4.0 2.4 Dark, brown grease. 10.6 0.2 do 6.8 Off-white, chalky polymer (insoluble). 2b 3.7 Dark brown plastic (soluble).

10.6 0.2 Acetone 7.7 Off-white amorphous solid.

2.1 0.04 Methylformate. 1.2 Ofi-white amorphous solid (soluble). 0.1 Off-white amorphous solid (insoluble).

2.6 0.05 Aeetonitrlle 1.3 Do. 0.1 Ofi-white amorphous solid (soluble).

3.5 0.666 MethanoL. 2 1 Ofi-white chalky solid. 2.1 0.04 Ethan 1.7 Do. 2.1 0.04 Isopropanol 0.20 1.9 Do.

This polymer is the material of Example I, and is repeated here for comparison.

In this table, three runs are shown which are divided into two parts, (a) and (b). These runs were actually carried out by the same procedure as the other runs, except that a portion of the polymer was found to be soluble in the excess labile hydrogen-containing compound. The soluble and insoluble portions were separated by filtration, followed by evaporation of excess labile hydrogen compound.

EXAMPLE III A run was carried out in which a mixture of acrylonitrile and acetone was subjected to the rays from a mercury lamp. In this run, 10.6 grams (0.2 mol) of acrylonitrile and 58 grams (1.0 mol) of acetone were charged to a quartz flask which was illuminated by 100 watt, high pressure, mercury vapor lamp. This ultraviolet irradiation was carried out at room temperature and atmospheric pressure for 4 hours. The product was then recovered by the method of Example I. The product amounted to 01 gram of tan amorphous solid. An elemental analysis of this material showed 65.0 weight percent carbon. 7.0 weight percent hydrogen and 21.5 weight percent nitrogen. The

wherein a portion of the product was soluble in the excess labile hydrogen-containing compound.

EXAMPLE V The polymers which were prepared in the above examples were then dyed with acidic, neutral and basic dyes.

In these runs, the procedure employed involved stirring 0.1 gram of the dye in 50' ml. water, after which the solution was filtered to remove excess dye. The acrylonitrile polymer was then added to the dye solution and stirred in the solution for 15 minutes. The polymer was then removed, water-washed on a filter and dried. The color intensity of the dyed polymer was then estimated. A polyacrylonitrile which was prepared by polymerization under gamma irradiation at a total dose to 10 Roentgens, and in the absence of a labile hydrogen-containing compound, was dyed by the same procedure. The dyed, modified acrylonitrile polymers of this invention were compared to this control run.

The results of these runs are expressed below in Table III.

TABLE III Dye rating 1 Mol acrylonitrile Acidic Neutral Polymer per mol from Run Labile H comlabile H Neolan Rose Brilliant Basic rho- N 0. pound used compound Initiator blue 3 Eosm 4 bengal blue 6 Violet 7 damine I Control None Game"... 3 2 2 1 1 9 Acetone 0. 2 do 13 10 10 2 3 11 2.0 do 7 4 4 2 2 10 0. 2 AIBN- 8 6 6 2 3 8 2.0 AIBN- 5 1 3 1 1 2 0.2 Gamma 4 0 1 2 3 1 0.2 AIBN 2 0 0 2 1 0 0. 2 AIBN 1 0 0 2 3 0 0. 178 Gamma 6 3 5 2 2 3 0. AIBN 12 9 ll 2 3 6 0. 2 Gamma 9 5 7 2 3 5 0.2 .do- 10 7 8 2 3 4 0. 2 --..do 11 S 9 2 3 7 1 This polymer was an unmodified polyaorylonitr ile prepared by the method of Example I, but with no labile H compound present.

'- Ranking by relative color intensity: 0 3 N eolan blue 2R-526B (CIBA) 4 Eosin (Eastman).

5 Rose Bengal (East-man, Technical).

lightest, 13 darkest.

6 Celanthrene Brilliant, Blue FFs-l3l-l35l5 Lot 401 (Du Pont) 7 Celanthrene Violet CB D31-08542 (Du Pont).

8 Rhodamine 5 GDN (Du Pont). infrared spectrum of this product was very similar to the spectrum of the product of Example 1.

EXAMPLE IV It can be seen that the modified polymers of this invention have increased dye receptivity. The increased dye receptivity is particularly noticeable when ocidic dyes are employed.

The products of this invention are useful in synthetic fibers and as molding resins. They can be blended with other acrylic polymers to provide reactive groups in the blend.

Reasonable variation and modification are possible within the scope of the foregoing disclosure and the appended claims to the invention, the essence of which is that it has been found that a modified polymer of at least one of acrylonitrile and methacrylonitrile can be prepared by subjecting the same together with a labile hydrogencontaining compound to at least one of ionizing and TABLE II Charge Product Mols acrylonitrile Grams Bun No. acrylonitrile Labile H compound Mols Labile compound Grams AIBN Wt. grams Appearance Ofi-vghite amorphous solid! Tan amorphous solid (soluble).

Tan amorphous solid (insoluble). Ofi-white amorphous solid (insoluble). Oil-white amorphous solid (soluble). Ofiwl1ite amorphous solid (insoluble). Tau amorphous solid (soluble). Off-white amorphous solid.

Tan amorphous solid.

Yellow solids (insoluble).

Brown viscous liquid.

1 Azobisisobutyronitrlle.

2 The infrared spectrum of this polymer was similar to that of the polymer in Example I.

In Table II, 4 runs are shown in two portions, these runs being of the same type as described in activating rays, as herein described, obtaining products Example II as herein set forth in which the nitrile group has been modified also as set forth, said products having a greatly improved dye receptivity, that a method for producing an improved dyed polymer has been set forth comprising preparing a modified polymer, as herein set forth and described, and then dyeing the same, that the modified polymers produced with gamma radiation are superior, as noted, and that such modified polymers, as herein described, have been provided advantageously by said method.

I claim:

1. A method for the production of a modified polymer from at least one monomer selected from the group consisting of acrylonitrile and methacrylonitrile, said polymer having improved dye receptivity, which comprises reacting said nitrile with at least one labile hydrogen-containing compound selected from the group consisting of wherein R is selected from the group consisting of primary and secondary alkyl radicals, containing from 1 to 10 carbon atoms, n is a whole integer of from O to 2, inclusive, and R is selected from the group consisting of -R,

o (OHzh-E-O-R and -O-R, wherein R and n are as previously defined in the presence of a free radical generating agent.

2. A method according to claim 1 wherein said labile hydrogen-containing compound is selected from the group consisting of acetone, methyl formate, acetonitrile, methanol, ethanol, and isopropanol.

3. A method according to claim 1 wherein said free radical generating agent comprises actinic radiation.

4. A method according to claim 3 wherein the temperature is in the range 25 C. and 75 C., the weight ratio of unsaturated nitrile to said compound is within the range of 1:10 and 1:200.

5. A method according to claim 3 wherein said actinic radiation used is gamma radiation.

6. A method according to claim 5 wherein the dose rate is in the approximate range to 10 Roentgens per hour (rep units), and the total dosage is in the approximate range of from 10 to 10 Roentgens.

7. A method according to claim 4 wherein said actinic radiation are activating rays which have a wave length in the range 3800 angstroms.

8. A method of producing a dyed modified polymer by steps comprising reacting at least one monomer selected from the group consisting of acrylonitrile and methacrylonitrile with a labile hydrogen-containing compound selected from the group consisting of wherein R is selected from the group consisting of primary and secondary alkyl radicals, containing from 1 to 10 carbon atoms, n is a whole integer of from 0 to 21 inclusive, and R is selected from the group consisting of R,

UNITED STATES PATENTS 2,982,761 5/1961 Campbell 260-855 2,794,793 6/1957 Coover 260-63 2,992,209 7/1961 Webb et al. 260-63 2,979,447 4/1961 Levine 204-154 2,027,311 3/1962 Levine et al. 204-154 2,527,863 10/1950 Webb 8-55 2,717,823 9/1955 Lowe 8-55 3,254,068 5/1966 Furrow 260-88.7 3,278,405 10/1966 Levine et al. 204-15922 HARRY WONG, JR., Primary Examiner US. Cl. X.R. 

1. A METHOD FOR THE PRODUCTION OF A MODIFIED POLYMER FROM AT LEAST ONE MONOMER SELECTED FROM THE GROUP CONSISTING OF ACRYLONITRILE AND METHACRYLONITRILE, SAID POLYMER HAVING IMPROVED DYE RECEPTIVITY, WHICH COMPRISES REACTING SAID NITRILE WITH AT LEAST ONE LABILE HYDROGEN-CONTAINING COMPOUND SELECTED FROM THE GROUP CONSISTING OF 